class ActiveModelSerializers::Adapter::JsonApi::ResourceIdentifier

def self.for_type_with_id(type, id, options)
  return nil if id.blank?
  {
    id: id.to_s,
    type: type_for(:no_class_needed, type, options)
  }
end

def self.type_for(class_name, serializer_type = nil, transform_options = {})
  if serializer_type
    raw_type = serializer_type
  else
    inflection =
      if ActiveModelSerializers.config.jsonapi_resource_type == :singular
        :singularize
      else
        :pluralize
      end
    raw_type = class_name.underscore
    raw_type = ActiveSupport::Inflector.public_send(inflection, raw_type)
    raw_type
      .gsub!('/'.freeze, ActiveModelSerializers.config.jsonapi_namespace_separator)
    raw_type
  end
  JsonApi.send(:transform_key_casing!, raw_type, transform_options)
end

def as_json
  return nil if id.blank?
  { id: id, type: type }
end

def id_for(serializer)
  serializer.read_attribute_for_serialization(:id).to_s
end

def initialize(serializer, options)
  @id   = id_for(serializer)
  @type = type_for(serializer, options)
end

def type_for(serializer, transform_options)
  self.class.type_for(serializer.object.class.name, serializer._type, transform_options)
end